1. Field of the Invention
The present invention relates to an input device that inputs information according to an approach state of an object using a change in capacitance or the like, a method of controlling the input device, and a program and, particularly, to an input device that inputs information according to an operation of a finger, a pen, or the like in various information devices such as a computer.
2. Description of the Related Art
Since a sensor that detects a change in capacitance can detect the approach of an object (for example, a finger or a pen) with a simple configuration, the sensor is widely used for user interface devices of various electronic devices, such as touch pads of notebook type computers or touch panels of smart phones.
In International Publication No. WO 2012/117437, a touch panel device including a touch panel unit in which a plurality of electrodes are arranged is described. A scan electrode is determined from among the plurality of electrodes of the touch panel unit, and the touch panel unit is operated for the determined scan electrode. Accordingly, a measurement value reflecting a change in capacitance of each electrode is acquired, and it is detected whether the touch panel unit is touched on the basis of the acquired measurement value.
However, since such an input device is required to sensitively detect the approach of an object to a detection surface of a sensor, there is a problem in that the sensor is particularly susceptible to external electromagnetic noise. For example, in the case of the above-described capacitive sensor, since a change in capacitance of an electrode caused by the approach of an object is detected as a small change in the amount of charge, there is a problem in that an error is easily generated in a detection result of coordinates of an object due to an influence of noise.